Min Yin (Casey) Yap

Assisted GPS

Introduction Without much doubt, most of us, if not all, are aware of what is the GPS (Global Positioning System) technology. Though we know about the advantages of GPS, it suffers from three significant limitations:

Limitations of GPS 1)The mobile unit must locate and receive signals from at least four satellites to be able to determine its location. This process of locating satellites, receiving the data and achieving a position fix may take several minutes. This delay is problematic to real-time applications, such as the location-based services.

2)The mobile unit needs a clear view of the sky to successfully receive signals from the satellites. Under unfriendly conditions, such as in building, in urban ‘canyons’, accuracy of the position fix can be compromised.

3)Finally, there remain questions of cost, size and power consumption when incorporating GPS receivers into trendy, miniature handsets.

Introducing Assisted-GPS (A-GPS)